Selective sweep

Abstract

A selective sweep is a rapid increase in the population frequency of an allele favored by natural selection. When an allele sweeps through a population, nearby neutral alleles sharing a chromosome with the favorable allele will increase in frequency due to genetic hitchhiking. In a classic selective sweep, a new advantageous mutation arises in the population and rapidly reaches fixation, resulting in an allele substitution. Classic sweeps have been rare in human evolution over the past 250,000 years, and there are only a few examples of classic sweeps after the divergence of continental human populations. Examples of classic sweeps in humans include a missense variant in the SLC24A5 gene resulting in lighter skin pigmentation in European populations, and a Duffy blood group variant that confers resistance to malaria in African populations.